ИСТИНА

The aim of present work consisted in preparation of soluble ceramics in the CaO-Na2O-SO3 system based on homogenized powder mixture of sodium sulfate NaSO4 and CaSO4.2H2O precipitated from solutions. Phase composition of powder mixture after homogenization in acetone in planetary mill except starting salts included hydrated double sodium calcium sulfate Na4Ca(SO4)3.2H2O. Phase composition of ceramics prepared at molar ratio CaSO4.2H2O/Na2SO4 =1 after firing at temperatures in interval 600-800 oC consisted of calcium sulfate anhydrite CaSO4 and double sodium calcium sulfate (Na0,8Ca0,1)2SO4. Density of samples increased from 1,2-1,3 g/sm3 for pressed powder compacts to 1,9-2,2 g/sm3 (70-80% respectively to theoretical density of glauberite Na2Ca(SO4)2) for ceramics after firing. The solubility test showed that the weight loss of ceramic samples of 15% and 75% occurred after exposure in water for 5 min and 60 min, respectively.Ceramics in the CaO-Na2O-SO3 system as a simple granules or complicated forms prepared via 3D printing technology can be used as a sacrificial (soluble or leachable) porogen and/or a prototype of porous space with given architecture for creation of porous polymer or inorganic materials. RFBR supported this study under Grant No. 20-03-00550.